Colorectal cancer

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Research in colorectal cancer

We are always learning more about cancer. Researchers and healthcare professionals use what they learn from research studies to develop better practices that will help prevent, find and treat colorectal cancer.

The following is a selection of research showing promise for colorectal cancer. We’ve included information from PubMed, which is the research database of the National Library of Medicine (NLM). Each research article in PubMed has an identity number (called a PMID) that links to a brief overview (called an abstract). We have also included links to abstracts of the research presented at meetings of the American Society of Clinical Oncology (ASCO), which are held throughout each year.

Reducing the risk of colorectal cancer

Some substances or behaviours may lower your risk of developing colorectal cancer. The following is noteworthy research into ways to lower your risk.

Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin) and naproxen (Naprosyn), have been linked to a lower risk of developing colorectal cancer (Cancer Epidemiology, Biomarkers & Prevention, PMID 25613116; International Journal of Cancer, PMID 24599876). Research has shown that a person’s genesgenesThe basic biological unit of heredity passed from parents to a child. Genes are pieces of DNA and determine a particular characteristic of an individual. may also play a role in how much lower the risk of colorectal cancer is if they take aspirin or other NSAIDs. People who have a certain genetic makeup (called a genotype) may benefit more than others from taking aspirin and other NSAIDs to lower their risk of colorectal cancer (JAMA, PMID 25781442). Aspirin may even help to prevent colorectal cancer from coming back, or recurring (ASCO, Abstract 3504). More research is still needed to further our understanding of the role that aspirin and NSAIDs may play in preventing colorectal cancer.

Statins are drugs that lower cholesterol levels in the body. Some research suggests that statins may lower the risk of colorectal cancer (World Journal of Gastroenterology, PMID 24587664). There is also some evidence that statins may help lower the risk of colorectal cancer better in men than in women (Cancer Causes and Control, PMID 23361340).

High amounts of calcium from your diet or supplements may lower the risk of developing colorectal cancer. Researchers have also shown that eating dairy products, which are high in calcium, may lower the risk of developing colorectal cancer (International Journal of Cancer, PMID 24623471; Cancer Epidemiology, PMID 23491770). Other studies have found that calcium may lower the risk of developing adenomas in the colon and rectum (International Journal of Cancer, PMID 25156950). Adenomas in the colon and rectum are precancerous growths, which mean that they can become cancer over time. Researchers have also suggested that the link between eating dairy products and a lower risk of colorectal cancer may be more related to calcium or vitamin D found in dairy products. More research is needed to determine how calcium and eating dairy products may lower the risk of developing colorectal cancer.

Find out more about research in reducing the risk of cancer.

Screening

Screening tests help find colorectal cancer before any signs or symptoms develop. When cancer is found and treated early, the chances of successful treatment are better. The following is noteworthy research into screening for colorectal cancer.

The stool DNA test is a promising way to screen for colorectal cancer (New England Journal of Medicine, PMID 24645800). This test finds DNA markers in cells that are shed into the stool from precancerous adenomas (also called adenomatous polyps) and cancerous tumours in the colon. The stool DNA test is being used in people who have an average risk for developing colorectal cancer. It may be easier for people to do than other screening tests for colorectal cancer because it isn’t invasive, and you don’t need to clear the intestine (called bowel preparation) or restrict your diet before you do the test. The stool DNA test may find some types of adenomas in the colon better than the fecal immunochemical test (FIT) used in colorectal screening (PLoS One, PMID 24465639). Cologuard is a stool DNA test that has been approved in the US, but it hasn’t been approved for use in Canada yet (JAMA, PMID 25514307).

Flexible sigmoidoscopy is being studied as a screening test for colorectal cancer in people between the ages of 50 and 64. A flexible sigmoidoscopy lets the doctor look at the lining of the rectum and lower part of the colon (called the sigmoid colon) using a flexible tube with a light and lens on the end (called an endoscope). Some research shows that people who had a flexible sigmoidoscopy were less likely to develop colorectal cancer or die from it than a group of similar people who didn’t have the screening test. The studies only compared flexible sigmoidoscopy to no screening. They did not compare it to other screening tests, such as fecal occult blood test (FOBT) or FIT. More research is needed to find out it flexible sigmoidoscopy should be used instead of, or along with, other screening tests (BMJ, PMID 25881903; Gastrointestinal Endoscopy, PMID 25708757; World Journal of Gastroenterology, PMID 25561818; JAMA, PMID 25117129).

Virtual colonoscopy uses a CT scan to create images of the colon without having to insert a colonoscope into the rectum. A virtual colonoscopy (also called CT colonography) is less invasive and more comfortable than a regular colonoscopy. Some drawbacks of this test are exposure to radiation, having to travel to centres that have a CT, the fact that CT scan can’t find very small polyps and the need for a regular colonoscopy if the CT scan finds an abnormal area. More research is needed to find out what role virtual colonoscopy may have in screening for colorectal cancer (Clinical Radiology, PMID 26145187; World Journal of Gastroenterology, PMID 25492999; European Journal of Radiology, PMID 22749108).

Capsule endoscopy (also called PillCam colon endoscopy, or capsule colonoscopy) is being studied as a screening test for colorectal cancer. In this test, the person needs to clear the intestine (called bowel preparation) and then swallow a tiny pill (capsule) containing a camera. The camera takes pictures as it moves through the digestive tract and is passed from the body. Doctors look at the pictures taken by the camera in the pill to see if there are any polyps or other abnormal areas in the colon or rectum. Studies show that capsule endoscopy works best to examine the lining of the colon when it was thoroughly cleansed. Capsule endoscopy does not seem to be as good as colonoscopy at finding polyps or abnormalities. Most research suggests that capsule endoscopy is best used after a positive fecal-based screening test such as FOBT or FIT. It may also be a good alternative to regular colonoscopy in people who don’t want to have this procedure (Clinical Gastroenterology and Hepatology, PMID 26133904; Gastroenterology, PMID 25620668; World Journal of Gastroenterology, PMID 25516644, PMID 25469027). More research is needed to see if capsule endoscopy has a role in screening for colorectal cancer.

Blood tests for colorectal cancer screening are starting to become available in Canada. Cologic and Sept9 are examples of blood tests (also called serologic tests) that researchers are studying in colorectal cancer screening. These blood tests look for biomarkers, which are naturally occurring substances in the body. When there is a change to the normal amount of a biomarker, it may mean the person has cancer or a precancerous condition. A positive blood test result may suggest that you have a higher than average risk of developing colorectal cancer. Blood tests aren’t part of provincial and territorial colorectal cancer screening programs and are not covered by provincial and territorial health plans. Blood tests are an attractive alternative to screening with stool samples that you have to collect at home. More research is needed to find out if these biomarkers or other biomarkers in blood are useful in screening for colorectal cancer (Biomarkers in Medicine, PMID 25123042; PLoS One, PMID 24901436, PMID 23049919; Gut, PMID 23408352; International Journal of Cancer, PMID 22696299).

Find out more about research in screening and finding cancer early.

Diagnosis and prognosis

A key area of research looks at better ways to diagnose and stage colorectal cancer. Researchers are also trying to find ways to help doctors predict a prognosis (the probability that the cancer can be successfully treated or that it will come back after treatment). The following is noteworthy research into diagnosis and prognosis.

Gene-based tests find differences between normal genes and genes that are changed, or mutated, in cancer cells. There are different types of gene-based tests. Microarray analysis is a type of gene-based test that allows researchers to look at many genes together to see which ones are turned on and which ones are turned off. Analyzing many genes at the same time to see which are turned on and which are turned off is called gene expression profiling. There are also gene-based tests that look for mutated genes. Researchers hope that developing more gene-based tests will help doctors identify the best treatments for certain cancers, including colorectal cancer. Gene-based tests may also help doctors tailor more treatments to each person’s cancer based on their unique genetic makeup (ASCO, Abstract e14631; Journal of Gastrointestinal Cancer, PMID 24989938; Gastroenterology Report, PMID 24759962; Annals of Surgery, PMID 23295318).

Virtual colonoscopy may be used as a diagnostic test for colorectal cancer. A large study that looks at all the results of smaller individual studies (called a meta-analysis) found that it may be a useful tool for diagnosis if a person has symptoms of colorectal cancer. This is an attractive alternative to regular colonoscopy as explained above. It is also more attractive than a barium enemabarium enemaA procedure used to x-ray the esophagus, stomach, small intestine or large intestine. A contrast medium (barium) is used to make organs and structures show up clearly on the x-ray image., which may also be done to help diagnose colorectal cancer. Some research shows that virtual colonoscopy is almost as good as colonoscopy and better than barium enema at finding colorectal cancer (Health Technology Assessment, PMID 26198205; World Journal of Gastroenterology, PMID 24587676; Lancet, PMID 23414650, PMID 23414648).

People with colorectal cancer who are physically active have a lower risk of dying from the disease than those who aren’t physically active. A study showed that people with colorectal cancer who are physically active for 7 or more hours a week have a 31% lower risk of dying of any cause compared to those with the disease who aren’t physically active (Journal of Clinical Oncology, PMID 25488967, PMID 23341510; International Journal of Cancer, PMID 23580314).

Aspirin may help improve survival in people with colorectal cancer who have a mutation in the PIK3CA gene. This mutation can make cancer cells grow and spread. A study found that people with a PIK3CA gene mutation who regularly take aspirin may survive longer than those with the mutation who do not take aspirin. Testing for the PIK3CA mutation may identify people with colorectal cancer who would benefit from taking aspirin (New England Journal of Medicine, PMID 23094721).

Metformin (Glucophage) is a drug used to control diabetes. Some research shows that people with colorectal cancer who take metformin to control their diabetes may survive longer than those with diabetes and colorectal cancer who do not take metformin. More research is needed to understand how metformin may help people with colorectal cancer survive longer (ASCO, Abstract e14541, Abstract e14521).

Find out more about research in diagnosis and prognosis.

Treatment

Researchers are looking for new ways to improve treatment for colorectal cancer. Advances in cancer treatment and new ways to manage the side effects from treatment have improved the outlook and quality of life for many people with cancer. The following is noteworthy research into treatment for colorectal cancer.

Surgery

The following is noteworthy research into surgery for colorectal cancer.

Laparoscopic surgery uses a thin, tube-like instrument with a light and lens (called a laparoscope) to remove tissue or organs through small incisions, or surgical cuts, in the body. Researchers are trying to find out if laparoscopic surgery is a good alternative to surgery through a larger cut in the abdomen (called open surgery) to remove rectal cancer. So far results show that laparoscopic surgery is just as effective in removing the tumour and preventing recurrence as open surgery. The advantage of laparoscopic surgery is that it is linked with less blood loss and shorter hospital stays compared to open surgery. Bowel function also returned to normal more quickly for people who had laparoscopic surgery (New England Journal of Medicine, PMID 25830422; Lancet Oncology, PMID 23395398).

Robotic surgery is a type of laparoscopic surgery. During robotic surgery, the surgeon sits near the operating table and controls robotic arms to remove tissue through several small incisions in the abdomen. The robotic arms have hinged instruments that turn and bend like the human wrist. The specialized instruments make this approach more precise than laparoscopic surgery, but they are very expensive and not widely available. Researchers are studying robotic surgery in people with colorectal cancer. People who have robotic surgery tend to lose less blood during the operation and have shorter hospital stays compared to those who have open surgery or laparoscopic surgery. Robotic surgery often is a longer procedure than open surgery or laparoscopic surgery (PLoS One, PMID 26214845; World Journal of Surgical Oncology, PMID 25885046, PMID 25169141; Journal of Surgical Research, PMID 25770742).

Find out more about research in cancer surgery.

Chemotherapy

The following is noteworthy research into chemotherapy for colorectal cancer.

TAS-102 is a chemotherapy drug that combines trifluridine and tipiracil hydrochloride. It is taken by mouth. Researchers are studying TAS-102 as a treatment for metastatic colorectal cancer that didn’t respond to other treatments (called refractory metastatic colorectal cancer). A phase III study compared TAS-102 to placebo. It found that those who received TAS-102 survived longer than those who had the placebo (New England Journal of Medicine, PMID 25970050).

Hepatic artery infusion (HAI) delivers chemotherapy drugs into the main artery of the liver (called the hepatic artery) through a catheter connected to a pump. Researchers are studying HAI as a treatment for colorectal cancer that has spread (metastasized) to the liver. Results so far show that this is a promising technique for treating liver metastases (Current Oncology, PMID 24523608).

Find out more about research in chemotherapy.

Targeted therapy

The following is noteworthy research into targeted therapy for colorectal cancer.

Ramucirumab is another type of anti-angiogenesis drug that blocks VEGF. Researchers are studying ramucirumab as a second-line treatment along with FOLFORI in people with metastatic colorectal cancer. A phase III study found that people who were given ramucirumab and FOLFORI survived longer than those who were given a placebo and FOLFORI (Lancet Oncology, PMID 25877855).

Find out more about research in targeted therapy.

Radiation therapy

The following is noteworthy research into radiation therapy for colorectal cancer.

Radioembolization is radiation therapy that uses microspheres (such as TheraSphere). Radioembolization may also be called selective internal radiation therapy (SIRT). Researchers are looking at radioembolization as a way to treat liver metastases in people with colorectal cancer. Microspheres are tiny glass beads that contain a radioactive isotope, such as yttrium-90. The microspheres are injected into the hepatic artery. They then become stuck in the small blood vessels of the tumour and deliver radiation to the tissue. Most research so far has looked at using radioembolization in people with liver metastases that didn’t respond to 2 or more chemotherapy treatments (American Journal of Clinical Oncology, PMID 25374143; Annals of Surgical Oncology, PMID 25323474; Journal of Cancer Research and Clinical Oncology, PMID 24318568). Radioembolization was also recently studied as a consolidation treatment after chemotherapy in people with liver metastases. The goal of consolidation treatment is to destroy any cancer cells left after chemotherapy and help keep the cancer in remission longer (ASCO, Abstract e14662).

Find out more about research in radiation therapy.

Immunotherapy

Immunotherapy is a type of biological therapy that uses the immune system to help destroy cancer cells. Researchers are studying immunotherapy to see if it is an effective way to treat colorectal cancer. Results so far show that people who have microsatellite instability (MSI), a type of change to the genetic material (called DNADNAThe molecules inside the cell that program genetic information. DNA determines the structure, function and behaviour of a cell.) inside a cancer cell, may benefit most from immunotherapy but more research is still needed (Journal of the National Comprehensive Network, PMID 26285242).

Find out more about research in biological therapy.

Learn more about cancer research

Researchers continue to try to find out more about colorectal cancer. Clinical trials are research studies that test new ways to prevent, detect, treat or manage colorectal cancer. Clinical trials provide information about the safety and effectiveness of new approaches to see if they should become widely available. Most of the standard treatments for colorectal cancer were first shown to be effective through clinical trials.

Find out more about cancer research and clinical trials.

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